How much light is needed for pedestrians to use paths in urban forests after dark, and how can we minimize the negative impact of that light on skyglow and wildlife?

These are the questions that the interdisciplinary research project NorDark set out to study.

The project strived to develop new knowledge crucial to design for sustainability in the urban

after-dark environments. Research teams from six different disciplines participated in this

study. Each discipline made a distinct contribution to the overall project results.

Impact story

The research team has tested lighting scenarios in two selected locations in two Nordic

cities – Alesund in Norway and Uppsala in Sweden. Both locations are urban residential areas

located adjacent to a protected green zone. The paths in these locations are used by residents for recreation, commuting, and getting to and from local schools and childcare facilities.

According to project leader Ute Besenecker, “Based on preliminary observations, we’ve established that by designing lighting qualities carefully, less light can be used without compromising pedestrian usability of these green areas.”

Key Findings

• Preliminary results from field work in Sweden and Norway suggest that lighting guidance and conditions in the areas studied could be adjusted to reduce lighting and its impact on wildlife without compromising human usability, thus also enabling reduced energy consumption.

• Snow cover can also affect light exposure, alertness, and melatonin suppression in residents. 

• The evaluation of the digital twin showed that the visual simulation of dark conditions with snow cover was more positively evaluated than the condition without snow.

• Urban forests hold potential for psychological restoration even with fixed and portable electric lighting after dark; lighting designed to reduce negative impacts on wildlife still supported pedestrians’ walking needs and, to some extent, provided positive experiences. 

• In addition, despite the presence of the lit path, a significant number of active species were observed and characterized during the dark season, creating a new database of wildlife presence linked with associated environmental conditions.

• The findings were informed by various methods, procedures and tools developed by the collaborating research groups. 

o Through site-specific digital twin tools, the testing of lighting scenarios and visualization of research outcomes were facilitated. 

o Through survey, questionnaire and interview practices, human input was collected in response to the site and lighting conditions. 

o Through consortium and stakeholder workshops, team communication and community engagement were facilitated. 

o Through camera and audio recording devices mounted off-the-path, wildlife behaviour was tracked and analyzed. 

o Through surveying of lighting conditions on site and review of lighting guidance, design interventions were developed and in situ experimentation was performed.

Several papers and dissemination activities have and will be produced that describe these processes.

Key outputs

• Dissemination to date:

10+ Articles, 1 Book, 5 Reports/Manuals, 14+ Conference Presentations and Proceedings, 10 Workshop activities (municipality and/or other stakeholders), several co-teaching activities between consortium members to each other’s students, 4+ published Master Theses, 1 doctoral dissertation finished, 2 doctoral dissertations in progress.

• Lighting prototypes and lighting strategies.

• Feedback between local stakeholders and team members, fostering new ideas for future research and application.

• Digital Twin prototypes for use and further research, education, and development by all stakeholders.

• Art installation in development, raising awareness and enabling exploration of multispecies negotiations related to outdoor lighting